hard question to answer because to many parameters can change.
here are the basics
nitrates 0-5ppm 5ppm max never more always less
ph solid @ 8-8.3
those are just basci h2O qualities of course there is calcium, alkalinity, and hardiness, and other test like copper and so on and so forth.
corals are supper hard to keep in big tanks like 55+ tanks, because they require nearly perfect parameters to thrive, and also the light system need to be on par with them if not they fade and then they die.
I suggest that if you are tyring to do a 10g nano reef you keep your parameter on spot, buy a reef kit, and buy essential minerals, this will help start preping you tank, also the age of the tank is a determining factor, because corals like to be in almost equal temp, parameters, and established systems, also check the fish and inverts you are getting for your CUC because some may affect you corals.
make the decision also are you going soft or hard corals, as hard require t-5 lights and they can run up your tab, also h2o changes are you religious about every week changes, or do you need a skimmer, all of these questions need to be answered before you even consider buying a coral, lets not say an anemone....woooo thats another story.
anyways I can help you set the tank up but patience and parameters is the key for your success in corals shoot me an email if you questions.